static int gic_init_bases()

in irq-gic.c [1150:1244]

• 70 lines of code
• 13 McCabe index (conditional complexity)

static int gic_init_bases(struct gic_chip_data *gic,
			  struct fwnode_handle *handle)
{
	int gic_irqs, ret;

	if (IS_ENABLED(CONFIG_GIC_NON_BANKED) && gic->percpu_offset) {
		/* Frankein-GIC without banked registers... */
		unsigned int cpu;

		gic->dist_base.percpu_base = alloc_percpu(void __iomem *);
		gic->cpu_base.percpu_base = alloc_percpu(void __iomem *);
		if (WARN_ON(!gic->dist_base.percpu_base ||
			    !gic->cpu_base.percpu_base)) {
			ret = -ENOMEM;
			goto error;
		}

		for_each_possible_cpu(cpu) {
			u32 mpidr = cpu_logical_map(cpu);
			u32 core_id = MPIDR_AFFINITY_LEVEL(mpidr, 0);
			unsigned long offset = gic->percpu_offset * core_id;
			*per_cpu_ptr(gic->dist_base.percpu_base, cpu) =
				gic->raw_dist_base + offset;
			*per_cpu_ptr(gic->cpu_base.percpu_base, cpu) =
				gic->raw_cpu_base + offset;
		}

		enable_frankengic();
	} else {
		/* Normal, sane GIC... */
		WARN(gic->percpu_offset,
		     "GIC_NON_BANKED not enabled, ignoring %08x offset!",
		     gic->percpu_offset);
		gic->dist_base.common_base = gic->raw_dist_base;
		gic->cpu_base.common_base = gic->raw_cpu_base;
	}

	/*
	 * Find out how many interrupts are supported.
	 * The GIC only supports up to 1020 interrupt sources.
	 */
	gic_irqs = readl_relaxed(gic_data_dist_base(gic) + GIC_DIST_CTR) & 0x1f;
	gic_irqs = (gic_irqs + 1) * 32;
	if (gic_irqs > 1020)
		gic_irqs = 1020;
	gic->gic_irqs = gic_irqs;

	if (handle) {		/* DT/ACPI */
		gic->domain = irq_domain_create_linear(handle, gic_irqs,
						       &gic_irq_domain_hierarchy_ops,
						       gic);
	} else {		/* Legacy support */
		/*
		 * For primary GICs, skip over SGIs.
		 * No secondary GIC support whatsoever.
		 */
		int irq_base;

		gic_irqs -= 16; /* calculate # of irqs to allocate */

		irq_base = irq_alloc_descs(16, 16, gic_irqs,
					   numa_node_id());
		if (irq_base < 0) {
			WARN(1, "Cannot allocate irq_descs @ IRQ16, assuming pre-allocated\n");
			irq_base = 16;
		}

		gic->domain = irq_domain_add_legacy(NULL, gic_irqs, irq_base,
						    16, &gic_irq_domain_ops, gic);
	}

	if (WARN_ON(!gic->domain)) {
		ret = -ENODEV;
		goto error;
	}

	gic_dist_init(gic);
	ret = gic_cpu_init(gic);
	if (ret)
		goto error;

	ret = gic_pm_init(gic);
	if (ret)
		goto error;

	return 0;

error:
	if (IS_ENABLED(CONFIG_GIC_NON_BANKED) && gic->percpu_offset) {
		free_percpu(gic->dist_base.percpu_base);
		free_percpu(gic->cpu_base.percpu_base);
	}

	return ret;
}